1. Field of the Invention
The present invention relates to a camera, and more particularly, to a camera having a proper exposure control function.
2. Description of the Related Art
In conventional cameras, when exposure is executed on only the point of a main subject, the actual scene may not be reproduced on the photographing picture.
For example, in a photograph taken with a blue sky as its background, since a film is preferentially exposed on a person, the blue portion of the sky acting as the background is not expressed in the photograph, and thus the mode of the actual scene is not expressed.
In particular, when a film having a narrow latitude is used or when photographing is executed using a digital camera, the above phenomenon may often occur.
A technology for exposing a main subject using information representing the brightness of a plurality of points in a photographing picture is disclosed in, for example, Jpn. Pat. Appln. KOKAI Publication No. 61-246711.
Further, in conventional cameras, when an AF (auto focusing) sensor has an optical system different from a photographing optical system, the AF sensor detects a different region with respect to a photographing field of view depending on a focal length of the photographing optical system.
Therefore, when, for example, the photographing optical system has a short focal length, the field of view of the AF sensor is narrower than the photographing field of view and a region smaller than an ordinary spot field of view is observed, thereby a measuring accuracy is liable to be lowered.
Further, when the photographing optical system has a long focal length, the field of view of the AF sensor is wider than the photographing field of view and has a large region which is not suitable as an ordinary spot field of view.
Japanese Patent No. 2934712 discloses a camera for determining first counterlight by automatic measurement of light (AE) as well as determining second counterlight by automatically detecting a focal length (using an AF sensor) in order to properly control exposure.
That is, in this camera, when a main subject is small or when counterlight cannot be measured by automatic exposure (AE), exposure can be properly controlled by determining counterlight by an AF sensor.